For 1: 1 CD backups, a device with a firmware that does not correct checksum read errors would be a good starting point. If the device behaves like this, it would be the closest thing to KryoFlux for CDs that I can think of.

No idea if such unit ever existed, but it would be probably like one of those old LG drives capable of ripping GC/Wii games using a weird mix of specific units, custom proprietary tools and hacked firmwares. Gave a quick look on the redump.org forum as they've started archiving more recent pc games, and it's mostly the same situation.

To be frank, given the abundance of custom retro hardware like the OSSC, Everdrives, GCLoader, etc, I'm surprised nobody ever built a "dumb" cd/dvd drive dumper - Like, a raw "read first ask questions later" kind of device.

noisymemories wrote on 2021-01-06, 12:07:

To be frank, given the abundance of custom retro hardware like the OSSC, Everdrives, GCLoader, etc, I'm surprised nobody ever built a "dumb" cd/dvd drive dumper - Like, a raw "read first ask questions later" kind of device.

Well, there are (were) socalled CD Duplicators.
These were little computer units in the size of a CD-ROM drive.
They could read from a source drive and then write to several destination drives (CD-Writers).

I think the problem with optical devices is, that they are too smart.
Just think of the ability of DVD drives to remember the annoying regional code thing.

By comparison, a floppy drive is pretty dumb, almost as analogue as a tape recorder.
That's why Kyroflux can record things like the strength of the field of the magnetic surface of a floppy.

A game cardridge (Master System, Genesis) is also very basic, it barely contains more than a ROM chip and some battery-backed RAM.

- With the exception of Nintend. systems. They usually had mappers or co-processors included. 😉

Those ancient MFM/RLL HDDs using a Shugart interface were also pretty dumb, I think.
Problem with emulation is, that the bandwith and timings are much higher than that of a floppy.
Emulating either the HDD itself or the interface controller needs FPGAs.
Normal microcontrollers are too weak to emulate these in real-time.
And a Raspberry Pi-like SBC might be having too much of a latency, not sure..

IIRC the issue with the raspberry is not the latency but the bandwidth of the GPIO headers, they're way too slow to sustain the required transfer speed of a CD/DVD unit controller.

By the way, even if we're not talking here about a full controller replacement - just the required commands for identifying and reading the disc - this would require swapping the mcu with a custom FPGA or entirely replacing the mainboard, not something for the faint of heart (Or, fat chance, someone finds out that a widely available DVD/Blue ray reader ships with an easily reprogrammable firmware ).